Because of the space confinements within an aircraft, coupling assemblies for interconnecting tubular conduit members are often located at places within the aircraft which are difficult to reach, to see and to service. Thus, it is desirable to have couplings which can be easily manipulated with one hand by the mechanic for closure while having redundant locking features. Also, if the coupling needs to removed or replaced, it should be possible for the mechanic to manipulate the release of the redundant locking features with one hand.
Numerous couplings have been devised which are intended to be manipulated with one hand. However, none of these provide the simple and cost efficient locking device with redundant features as is found in the present invention. Prior art devices which are deemed relevant to the present invention are described below.
Although couplings with spherical shoulders are known to produce less localized stresses and unwanted forces, they produce such great hoop stresses that they cannot be used in split clam-shell couplings with conventional hinges and latches.
U.S. Pat. No. 3,336,643 to Robinson discloses an adjustable wire fabric weapon securing apparatus in which a buckle pin fits into a curved area at the base of hooks. A toggle mechanism keeps the buckle pin in engagement with the hooks.
U.S. Pat. No. 3,999,825 to Cannon shows an over-center latch.
U.S. Pat. No. 4,008,937 to Flippi discloses a coupling assembly for coupling two tubular fluid conveying members together. It has a safety lock comprised of a locking clip which is positionable to cooperate with the catch defined by an enlarged lever end to latch the lever in its clamping position.
U.S. Pat. No. 4,249,786 to Mahoff shows a coupling having a plurality of oppositely extending latches which are spring-loaded at their hinges so as to be brought into latching engagement with latch pins upon squeezing the two sections of the coupling together.
U.S. Pat. No. 4,881,760 to Runkles et al. shows a conduit coupling with redundancy features. A locking mechanism includes locking edges which engage locking lips on a latch member. A similar device is shown in U.S. Pat. No. 4,900,070 to Runkles et al.
Other types of toggle connections are shown in U.S. Pat. No. 2,673,102 to Hutchinson; U.S. Pat. No. 2,869,211 to Kessler et al.; and U.S. Pat. No. 4,573,717 to Peacock.
Although each coupling described is suitable for its intended purpose, none can be operated with one hand and provided locking redundancy with a primary lock and a secondary lock.